Idiots who, despite knowing they're infected with something that will easily spread, take zero precautions, being so stupid about it that you'd swear they're doing it deliberately. For the last few days, I've been sick with a throat infection that made me feel like I was going to suffocate, all because someone decided to open cough all over me when I was queuing at a shop this weekend. Even if things like strep and the cold will inevitably spread around if anyone who's infected crosses paths with enough people who aren't, it's not hard to show a little decency and at least try to not give everyone else your germs.